Metrohm 746 VA Trace Analyzer - Manual (Page 315)

5.6 Method Specifications
746 VA Trace Analyzer / 747 VA Stand
5-164
Parameter Range; Default value / Meaning
Operators
The operators are processed from left to right. With nested expres-
sions, multiplication and division have precedence over addition and
subtraction.
= Equals (value assignment)
+ Addition
– Subtraction
* Multiplication
/ Division
( ) Brackets
Max. 4 pairs of brackets can be nested.
Standard formulae
Pressing the softkey
enters standard formulae in
this field which provide the mass concentration of the substances
referred to the sample size
S0 as a final result in g/L or g/g.
Automatic entry of the standard formulae depends on whether the
sample size has been entered as a weight or volume and whether
diluted or undiluted samples have been used (see also section 5.4.4).
The dependence of the put in sample size
S0 and the parameters of
the SMPL instructions is as follows:
S0 S2 V.fraction V.total Standard formula for final
result
Result
unit
L – – – MC: g/L
g d – – MC: / (S2 * 1000) g/g
L – V.fraction V.total MC: * V.tot / S0 g/L
g – V.fraction V.total MC: * V.tot / S0 g/g
The standard formulae listed above refer to the basic quantities g and
L, but the results are automatically supplied with the appropriate prefix
by the simultaneous entry of
#g/L or #g/g in the field Res.unit (see
Res.unit ).
Standard formulae can be altered at a later date to specify the result in
another unit (e.g. ppm) or for further calculation.
In the case of modifications to the method which also
influence the standard formulae, any existing standard
formulae must be deleted and then regenerated with the
softkey ).